1. Field of the Invention
The present invention relates to a plant cutting system, and more particularly to a cutter system utilized for dormant pruning in vineyards and similar applications.
2. Description of the Prior Art
Devices for performing pruning and thinning operations in vineyards have recently become more widely used. Such devices are used throughout various stages of the growing cycle to remove excess portions of the plant to control yield, maintain plant structure and increase fruit exposure. By removing the excess and/or aged portions of plant material, the plant, such as a grapevine, is able to focus more resources on the fruit so that quality is improved while attaining a desired yield. Although such operations have historically been performed by hand, the need for more efficient ways of performing such tasks has increased to improve the efficiency and economics of the vineyard.
To reduce or eliminate some labor costs, mechanical devices have been developed to perform several of these tasks. Hedger and sickle bar type devices have been developed and have proven useful to create a box shaped profile along the vineyard cordons and trellis systems. Although such hedging devices work well in some dormant pruning applications, for others, improvements or alternate approaches are needed. In an effort to meet this need, barrel type rotary pruners have been utilized. Barrel pruners generally include a series of rotary cutting assemblies with blades oriented about a generally vertical axis. In certain vineyard and trellis configurations, barrel pruners have performed well in dormant pruning operations. However, safety, wear and damage to plants and trellises are a concern. Some devices utilize high speed rotating saw blades, which may pose a safety concern and are expensive to maintain. Other devices utilize rotating guards, which may reduce costs for blade replacement, but may also have an irregular or unsatisfactory cut. Although such devices provide adequate cutting in many applications, for some uses a more precise cut may be needed for portions being removed. In particular, it is often desired for the final cuts along the sides and top of a vine cordon to be more precise and without splintering or shattering remaining plant portions. Moreover, utilizing a system that protects the blades while still performing satisfactory cutting has not been achieved by the prior art. In addition, maintaining proper rotational speed for performing the cutting, as the ground speed of the vehicle or chassis changes is not provided by the prior art.
Proper positioning of the cutters has also been a problem. Maintaining the cutters at the correct position and allowing the cutters to follow closely around posts without damage provides design challenges. Spring type or gas spring type systems have been utilized that allow deflection of pruner assemblies. However, such systems do not provide for easy adjustment and do not have proper damping and/or provide for proper positioning.
It can be seen then that a new and improved cutting system is needed for mechanized vineyard pruning operations. Such a system should provide for controllable cutting assemblies that react proportionally to the speed of travel to maintain consistent removal through improved proportional speed control. Such a system should provide safe and reliable cutting without damaging the cutting devices, the trellises or permanent stationary portions of the plants. Such a system should also follow around trellis posts and other obstacles while maintaining proper position. Moreover, such devices should provide for a precise lower and side cut. The present invention addresses these, as well as other problems associated with such plant cutting systems.
The present invention is directed to a cutting system for plants and in particular to a cutting system utilized for removing excess portions of plants trained on trellises, such as vertical shoot positioning trellises. The cutting system includes two first cutting assemblies, each having a stack of rotary cutter assemblies mounted about a substantially vertical rotational axis. The system mounts to a chassis so that the opposed first cutting assemblies extend on either side of trellises and remove undesirable portions of the plants. The cutting system also includes a pair of opposed second cutting assemblies mounted to perform side cuts to form a box type profile. In one embodiment, the second cutting assemblies are rotary type cutters that rotate about a substantially horizontal axis and make the side cuts. In another embodiment, the second cutting assemblies are reciprocating sickle bar type cutters that make the side cuts.
The first cutting assemblies are preferably pivotally mounted to a supporting frame so that the assemblies pivot away when engaging a post or other stationary objects, or when encountering resistance from the plant above a predetermined level. The rotary cutter assemblies include upper cutter assemblies with substantially rotating guards. The cutter assemblies with guards include a stationary cutter section that has cutter elements arranged to engage the plant; the guards are rotationally driven around a periphery of the cutters so that a shearing action with the stationary cutter elements is achieved.
An opener wheel is disposed within the stack of cutter assemblies to engage objects such as trellis posts and avoid damage to the cutter assembly. The opener wheel typically has a diameter slightly larger than the outermost diameter of the guards or cutter members. With this arrangement, the opener wheels engage the post or other stationary object to cause the cutting assemblies to deflect and/or cause to open, rather than the cutters striking objects. The cutting assemblies follow around trellis posts as the opener wheel engages the post to maintain the cutters away from engagement.
The first cutting assemblies also include a lower rotary cutter assembly. The lower cutter assembly includes a stationary cutter section and complementary rotating cutter section that work together to create a shearing action. The lower rotary cutters provide a precision cut that becomes a desirable finish cut over the remaining permanent portion of the plant. The lower cutter assembly has a slightly smaller diameter than the upper cutter assemblies to further decrease the chance of striking objects.
In one embodiment, the second cutting assemblies include a rotating cutter portion and a stationary cutter portion that are complementary to one another. The stationary and complementary cutter portions provide a precision cut forming a side of the box being formed on the trained plants. Guards provide added safety to the side cutters that are spaced forwardly or rearwardly from the first cutting assemblies to engage plants before or after the vertically stacked first cutting assemblies. In another embodiment, the second cutting assemblies are vertically extending sickle bar type cutters that form side cuts. In either embodiment, the second cutting assemblies may be positioned to precede or follow the first cutting assemblies.
The cutting assemblies include a hydraulic controller system. The control system provides for pivoting the cutting assemblies to an open transport position for entering and exiting vine rows and providing proper pressure and positioning during operation.
In operation, the rotational speed of the various cutter assemblies is maintained at a rate proportional to the ground speed through a controller. In this manner, the desired rate of plant engagement remains substantially constant, even as the travel speed varies. It has been found that a rotational speed of the periphery of the cutter assemblies greater than the ground speed is preferred. Rates of up to approximately three times the ground speed have provided excellent results. However, it can be appreciated that the proportional speed is easily changed with a programmable controller to optimize operations for variables such as trellis type, grape variety and/or terrain.
These features of novelty and various other advantages that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings that form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
Referring now to the drawings, wherein like reference numerals and letters indicate corresponding structure throughout the several views:
Referring now to the drawings, and in particular to
The cutting system 100 is configured for being supported on a frame 110 from above on a hanging mount 112. The hanging mount 112 includes an adjustment bracket 116 to vary the system position as needed. The mount 112 may hang on a boom mounted to a trailer or a self-propelled chassis. In the embodiment shown in
The first cutting assemblies 102 and 104 include several cutters 120, an opener wheel 122 and a lower cutter 124. The cutters 120 and 124 and the opener wheel 122 are mounted about a substantially vertical axle 126 in a stacked configuration. In a preferred embodiment, the axle is hex shaped to provide for easier mounting and drive. The axle 126 is driven from above by a hydraulic motor 114, which is powered, for example, by a power take off or a hydraulic pump on the chassis or tractor. The hydraulic lines are not shown for clarity. The cutters 120 and 124 are vertically aligned to combine with the cutters 106 and 108 to cut a box type profile when pruning portions of the grapevines.
An upper frame assembly 134 and a lower frame assembly 158 support the axles 126 of the cutting assemblies 102 and 104. A bearing hub 156 provides support and facilitates easy rotation. A pivoting support member 136 receives the axle supports 134 and 158 as well as individual cutter torque arms 154. The pivot member 136 is mounted to a pivot bearing assembly 190. The pivot bearing assembly 190 allows the first cutter assemblies 102 and 104 to pivot should they strike unintended objects, such as rocks, larger plant portions, or trellis posts. As shown most clearly in
The pivot bearing assembly 190 cooperates with the hydraulic control circuit 200, shown in
In the reducer/reliever mode, the 2-way valve 202 is positioned to expose the hydraulic cylinder 194 to the valve 208. At this position, the cylinder 194 has a reduced hydraulic pressure applied to it, causing a force in one direction to be applied. In the event that a greater external force in the opposite direction were applied to the cylinder 194, the cylinder would move in the opposite direction until the external force ceased to be greater. At that time, the reduced pressure would automatically re-extend the cylinder 194.
If the operator chose to manually open up the cutting assemblies 102 and 104, the reducer/reliever valve 208 is isolated from the cylinder 194 through the use of the 2-position, 2-way valve 202 and flow is directed through only the bi-directional valves 204 and 206. In this way, the 3-position, 4-way valve 208 is not interfered with in its normal operation.
Upon entering a row, the operator typically has the reducer/reliever valve 208 isolated, and the bi-directional control valve 204 is positioned with the cylinder 194 at the open position. As the cutting system 100 fully enters the trellis row and is ready to begin working, the valve 202 is changed so the reducer/reliever valve 208 is exposed to the cylinder 194, causing the cylinder 194 to close.
As a trellis post or other object approaches and comes in contact with the opener wheels, creating an external force greater than that of the reduced hydraulic pressure applied to the cylinder 194, the cylinder extends and allows the cutting assemblies 102 and 104 to open up and clear the post. The cylinder 194 then retracts and automatically closes the cutting assemblies 102 and 104 as it passes. The pressure needed to open the cutting assemblies may be varied by adjusting the valve 204.
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The control system 800 provides for maintaining the cutting assemblies at a constant proportional speed relative to ground speed. For example, the typical ground travel speed might be 1.5 miles per hour. The periphery of the cutting assemblies 102 and 104 may be driven at a typical speed of approximately 4 miles per hour with rotary speed indicated to an operator on a tachometer or other similar device. It has been found through testing that superior results are achieved when the relative speed of the cutting assemblies at periphery is approximately 2-3 times the ground speed. The control system also provides for varying the relative speed as conditions vary based on terrain, grape varietal, growing conditions, trellis and other parameters. Moreover, as the number and configuration of the various cutting assemblies are varied, the rotational speed might also be varied to achieve preferred results. The controller also preferably provides for maintaining the cutter assemblies at a rotational speed between rows at a minimum rotational speed, so the system 100 does not need to ramp up to cutting speed from a standstill. Once a row has been entered, the controller again maintains the proportional rotational speed.
In operation, the cutting system 100 is maintained so that the cutters are at a minimum rotational speed before entering a row. Once the row has been entered, the second cutting assemblies 106 and 108 or 306 and 308 first engage the canopy on either side of the trellis and provide precision side cuts to remove a portion below the canopy. As the first cutting assemblies 106 and 108 enter the row, the opener wheels 122 engage posts to maintain the cutting assemblies 102 and 104 at a position that prevents the cutters 120 and 124 from striking posts and causing damage. The pivot bearing assembly 190 and the hydraulic control system 200 provides tension. The present invention provides for easily modifying the configuration and number of cutting assemblies as well as the relative rotational speed of the assemblies through the control system 100 to maintain a precise high quality cut from the plants. The present invention provides for a safe, reliable cutting system 100 that achieves precise and controlled removal that is not possible with the prior art.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.